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<abridged> NASA's Asteroid Redirect Mission (ARM) has been proposed with theaim to capture a small asteroid a few meters in size and redirect it into anorbit around the Moon. There it can be investigated at leisure by astronautsaboard an Orion or other spacecraft. The target for the mission has not yetbeen selected, and there are very few potential targets currently known. Thoughsufficiently small near-Earth asteroids (NEAs) are thought to be numerous, theyare also difficult to detect and characterize with current observationalfacilities. Here we collect the most up-to-date information on the smallestknown near-Earth asteroids to outline the properties of these small NEAs ascurrently understood, in order to examine what the eventual ARM target might belike. Observational biases certainly mean that our sample is not an idealrepresentation of the true population of small NEAs. However our sample isrepresentative of the eventual target list for the ARM mission, which will becompiled under very similar observational constraints unless dramatic changesare made to the way near-Earth asteroids are searched for and studied.  We find that the typical rotation period is 40 minutes. The mean and medianaxis ratios were 1.43 and 1.29. Rotation rates much faster than the spinbarrier are seen, reaching below 30 seconds, and implying that most of thesebodies are monoliths. Non-principal axis rotation is uncommon. Axial ratiosoften reach values as high as two, though no undisputed results reach abovethree. We find little correlation of axis ratio with size. The most commonspectral type in the sample of small NEAs is S-type (> 90%), with only ahandful of C and X types known.

On the rotation rates and axis ratios of the smallest known near-Earth asteroids---the archetypes of the Asteroid Redirect Mission targets